This document explains key terms and data related to the detection of Highly Pathogenic Avian Influenza (HPAI) strains, specifically focusing on findings in Domestic Cats (Felis catus).
Date Detected: This indicates the date when a domestic cat tested positive for the Eurasian lineage goose/Guangdong H5 clade 2.3.4.4b through RRT-PCR testing.
HPAI Strain:
- EA (Eurasian): Refers to the Eurasian lineage of H5 viruses. It is important to note that EA H5 (2.3.4.4) viruses are known to be highly pathogenic to poultry.
- AM (North American): Denotes the North American lineage of H5 viruses.
- EA/AM: This signifies a reassortant virus strain, resulting from a mix of the H5 goose/Guangdong Eurasian lineage and the North American wild bird lineage.
The determination of virus lineage, subtype, and pathotype is based on cleavage site analysis derived from sequence data. This data is obtained directly from the sample or virus isolate. If the subtype is listed as incomplete, it could mean:
- Virus isolation and/or sequencing results are still pending for the specimen.
- The specimen was detected by the developmental H5 RRT PCR, which targets the Eurasian lineage goose/Guangdong H5 clade 2.3.4.4b, but further characterization was not possible. This is often due to a low level of virus or viral RNA in the sample.
Important Note on Domestic Cats (Felis catus) and H5N1:
Updated reporting as of September 3, 2024, includes all known feral and domestic cats that have tested positive for H5N1 at the National Veterinary Services Laboratories. Domestic cats, similar to other scavenging or carnivorous species, are generally considered dead-end hosts for this avian influenza virus. This means that while cats can be infected, they are not typically significant contributors to onward transmission of the virus. Notable exceptions could include transmission within close family groups of cats or in situations where cats roost together in high densities.
Due to increased public interest in the context of HPAI in dairy events, data includes all known positive Influenza A H5N1 detections in domestic cat species prior to March 1, 2024. These historical detections are also reported to the World Organisation for Animal Health (WOAH) World Animal Health Information System (WAHIS).
For submitting agencies who identify any data inaccuracies or omissions, please contact [email protected] with supporting documentation.
